Optimization options?

[Simon Marlow]

> User's Guide 6.2 says:
> 
> "So, when we want very fast code, we use: -O -fvia-C."
> 
> but I've seen programs which use the (apparently 
> undocumented) -O2-for-C flag too.

-O2-for-C was removed (from the docs at least) for three reasons:

  - it is equivalent to -optc-O2

  - GCC has a recent history of bugs in -O2, and we didn't want to
    encourage people to use known-broken compiler options.

  - it makes very little difference anyway.

Cheers,
	Simon